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Monday, August 25, 2014

“Some fluoride-containing products, however, have enough of
the ion to be hazardous and should be handled and stored with caution.For example, a 1.23 percent fluoride gel contains
12,300 ppm or 12.3 milligrams per gram [such as dentists' fluoride treatments]. Thus, one ounce (28.3) grams) contains
348 milligrams, a life-threatening dose for a 11.5 kilogram or a 25 pound
child.Even the popular fluoride
toothpastes may be hazardous to small children. These products typically
contain 0.1 percent fluoride or 1000 ppm.Thus, an eight ounce tube containing 226 milligrams of fluoride, could endanger
a 16 or 17 pound child…Therefore such products should be kept out of the reach
of those who are at risk."

“Dental fluorosis, a disorder of enamel mineralization which
can be produced only during the development of the enamel prior to tooth
eruption, is generally regarded as a toxic manifestation of chronic intake of
excessive fluoride.Exactly, how much
fluoride is too much is uncertain.”

Gary M.
Whitford, PhD, DMD, August 1981

“Fluorides:
Mechanism of Action Efficacy and Safety,”

Dental Caries Prevention in Public Health
Programs

Proceedings of
a Conference October 27-28 1980

Sponsored By the National Caries Program

National Institute of Dental Research

US Department of Health and Human Services

Edited by
Alice M. Horowitz and Hilah B. Thomas

Excerpts above and below by Gary M. Whitford, PhD, DMD

Dr. Nichols asks Dr. Whitford the following question: "If I gave you two items, one a 9 ounce size of Crest toothpaste another a 7 ounce bottle of 0.2 percent sodium fluoride solution, could you discuss the toxicity of each in relation to a 20 kilogram child?"

Dr. Whitford answers "There would be 225 mg of fluoride in the tube. The 7 ounce bottle is about 0.1 percent fluoride so it would contain about 200 mg of fluoride...I think that the potential for toxicity, if ingested all at once, would be about equal. Assuming that 30 mg of fluoride per kilogram of body weight is fatal, these doses would be dangerous for seven and nine kilogram children, respectively [15 to 20 pounds]. I'm unaware of any report indicating that death has occurred from the ingestion of toothpaste or a 0.2 percent sodium fluoride solution. It is, however, conceivable that it could happen. For that reason, when our children were younger, we purchased the 4 to 6 ounce tube of toothpaste and kept them out of their reach."

Fluoride is readily absorbed from the gastrointestinal
tract. That which appears in the feces is mainly if not entirely, unabsorbed
fluoride and usually accounts for only about 5 to 10 percent of the amount
ingested daily. Some factors, however, decrease the absorption of fluoride,
particularly divalent and trivalent cations such as calcium, magnesium and
aluminum. If high concentrations of these ions are present with the fluoride at
the time of ingestion, systemic absorption is reduced.

From the plasma, fluoride diffuses to the extra cellular and
intracellular fluids of the soft tissues where it rapidly reaches a steady-state
distribution.

As the plasma curve rises, so do the concentrations of
fluoride in the muscle, the liver, the heart, and all soft tissues

The excretion pattern of fluoride, however, is not exactly
this way in all people.The age of the
individual influences how much fluoride is removed from the body...The excreted percentage of a fluoride dose
generally varies as a direct function of age. The younger the individual, the
less excretion.The older the
individual, the more of a given dose is excreted.This result is attributable principally to
the growth rate and age of the skeleton and the surface area of bone mineral
available for fluoride uptake. In the growing individual, these factors favor
enhanced fluoride uptake so that relatively less is excreted in the urine.

According the some findings that we made a few years ago,
fluoride excretion is a function of the pH of the urine. At a low pH, fluoride
excretion is also low and as the urine pH rises, the rate of fluoride excretion
rises as well.

The diet of most infants is either mother’s milk or a formula
based on cow’s milk.The urine pH of infants who are solely formula fed is
generally lower, sometimes markedly so, then that of solely breastfed infants
and the would be expected to excrete less of the fluoride delivered to the
kidneys in the blood.Such differences
in excretion rate might or might not be desirable depending on the quantities
of fluoride involved.

Thus, difference in diet, among several other important
factors, will tend to produce urine pH values that approach one end or the
other of the physiologic range. These factors influence the uptake of fluoride
by developing teeth and the fluoride levels of the oral fluids. Therefore, they
can affect the cariostatic efficacy of fluoride in certain individuals or
perhaps the development of fluorosis in others.

Dental fluorosis, a disorder of enamel mineralization which
can be produced only during the development of the enamel prior to tooth
eruption, is generally regarded as a toxic manifestation of chronic intake of
excessive fluoride.Exactly, how much
fluoride is too much is uncertain.”…Probably no single dose, or narrow range of
doses can be determined because of several variables. The age and body weight
of the child or fetus, the frequency of the doses, the peak plasma levels, the
magnitude of the more sustained fasting plasma level, are among the factors to
be considered.Nevertheless, the early
data provided by Dean are pertinent.

According to his findings and classification system, when
the community index of fluorosis exceeds 0.6, the incidence and severity of fluorosis
begins to constitute a public health problem warranting increasing
consideration.This index value was
reached in communities with water fluoride levels of 1.6 to 1.8 ppm.Thus the margin of safety for avoiding a
degree of dental fluorosis which may be of public health concern is rather low
at somewhat less than two and is another reason for carefully monitoring
fluoride levels in water.